        form - formatter control and monitor (K4K3 racks)

            Syntax:     form=mode,rate,input,aux,synch,aux_start,output

            Response:   form/mode,rate,input,aux,synch,aux_start,output,daytime,st1
            ,st2,st3


Settable Parameters:
          mode      A, B, C, D. No default.
            rate        0.25, 0.50, 1.00, 2.00, 4.00 (default), 8.00
            Mbit/sec
          input     nor (default), ext, crc, low, high
          aux       up to 12 hex digits, default is no change
          synch     synch test on (default) or off
            aux_start   start new aux on next frm (default) or 1PPS
            output      nor (default), low, or high 

Monitor-only Parameters:
          st1       status byte 1, hex
          st2       status byte 2, hex
          st3       status byte 3, hex
          st4       status byte 4, hex

Comments:
The status of the formatter is not checked so it is necessary
to visual verify that the formatter is in remote. A future
implementation will have a different response:

                form/mode,rate,input,aux,synch,aux_start,output,test,sign,run/set,r
        em/lcl,pwr,daytime,threshold,pend,1pps,frame,data,tape,plo,srq

          test      fail or ok
          sign      synch polarity: + or -
          run/set   time set switch: run or set
          rem/lcl   remote/local switch: rem or lcl
        pwr     power interrupted: ok or pwr
        daytime date and time in format yydddhhmmss.sss
          threshold synch test threshold: nanseconds (values of
          13.9x1,2,4,8,16,32)
        pend    sample rate update: pend or ok
        1pps    external 1 PPS: 1pps or ok
        frame   clock: frame or ok
          data      clock: data or ok
          tape      clock: slip or ok
        plo     lock or unlocked
        srq     srq or ok

For longitudinal drives, the correlators can not reproduce
recordings made at speeds below 40 ips, but this limitation is
subject to change in the future. This limitation is
functionally equivalent to a minimum per track data rate of 2
Mbit/sec.
